FIX: Added choices to DataKeys dtype field
FIX: Added choices to DataKeys dtype field

hhslepicka/metadatastore,NSLS-II/metadatastore,tacaswell/metadataStore,tacaswell/metadataStore,arkilic/metadatastore,ericdill/databroker,hhslepicka/metadatastore,arkilic/metadatastore,ericdill/databroker,NSLS-II/metadatastore